But when I try to configure my php in the /usr/local/lib64/php53/php.ini file by replacing with the directive:session.save_handler = filesby the directive:session.save_handler = redisand I restart Apache, an http request is replied with a:HTTP Error 500 (Internal Server Error)

Same thing if I add the directive:session.save_path = "tcp://vpsXXXXX.ovh.net:6379?weight=1"

Same thing if I add the directive:session.save_path = "tcp://localhost:6379"